Benefit agents, such as perfumes, silicones, waxes, flavors, vitamins and softening agents, are expensive and generally less effective when employed at high levels in personal care compositions, cleaning compositions, and fabric care compositions. As a result, there is a desire to maximize the effectiveness of such benefit agents. One method of achieving this objective is to improve the retention of such benefit agents whilst formulated and aged in a formulated product composition and delivery efficiencies of such benefit agents. Unfortunately, it is difficult to improve the retention and delivery efficiencies of benefit agents as such agents may be lost due to the agents' physical or chemical characteristics, or such agents may be incompatible with other compositional components or the situs that is treated.
In an effort to improve the delivery efficiencies of benefit agents, the industry, in many cases, encapsulated such benefit agents. In one aspect, U.S. Pat. Nos. 4,001,140; 4,081,376; and 4,089,802 disclose a method for capsule formation utilizing a reaction between urea and formaldehyde. In one aspect, U.S. Pat. No. 4,100,103 discloses a reaction between melamine and formaldehyde. Forming microcapsules from urea-formaldehyde resin and/or melamine formaldehyde resin via polycondensation reaction are disclosed in U.S. Pat. Nos. 4,001,140; 4,081,376; 4,089,802; 4,100,103; 4,015,823; and 4,444,699. Alternatively, one can utilize interfacial polymerization with polycondensation to manufacture poly(urea) and/or poly(urethane) capsules. Such microcapsule walls are the reaction products of a reaction of a polyisocyanate with a polyamine and/or a polyol, and are disclosed in U.S. Pat. No. 6,248,364; EP 0537167 B1; and USPA 2002/0136773 A1. Alternatively, one can utilize complex coacervation methods to develop a wall around a dispersed benefit agent. Such microcapsule walls are the reaction products of anionic polymers and cationic polymers and/or surfactants, optionally followed by a crosslinking reaction. The use of cationic polymers such as gelatin with anionic polymers, such as polyphosphates or polysaccharides, are disclosed in U.S. Pat. No. 4,622,267. Alternatively, one can surround a benefit agent core with an inorganic shell. Such capsules are disclosed in WO 2009/106318A2.
Alternatively, one can employ acrylates and esters of acrylic acid to surround a benefit agent core, such capsules are disclosed in U.S. Pat. No. 6,951,836 B2, and USPA 2009/0289216 A1. One approach described in the art is to manufacture a porous bead comprising acrylate materials, which can then be subsequently loaded with benefit agents, such approaches are disclosed in U.S. Pat. No. 5,145,675; WO2000041528, U.S. Pat. No. 5,856,409; USPA 2005/0121143 A1, USPA 2005/0129759 A1, and U.S. Pat. No. 5,725,869. Another approach disclosed in the art is for the use of acrylates as enteric coatings, e.g. to trigger the release of benefit agents from a delivery system upon a change in pH, such approaches are described in WO 2005055990, USPA 2010/0003518 A1, WO 2008058868, U.S. Pat. No. 6,375,983, USPA 2002/0102286 A1. Another approach is to utilize interfacial polymerization, wherein acrylate monomers are dispersed in a hydrophobic benefit agent, followed by polymerization of the dispersed monomers which then migrate to an oil/water interface to form a shell that surround the benefit agent. Such approaches are disclosed in U.S. Pat. No. 5,292,835; USPA 2003/0125222 A1, and USPA 2005/0043078 A1. Such microcapsules are deficient in their ability to manage both leakage of the benefit agent, and controlling the release of the benefit agent during or after application to a situs.
Unfortunately, capsules manufactured using the aforementioned methods and raw materials have several drawbacks which include: (1) they cannot be formulated in certain classes of products due to strict formulation limits, (2) they have high permeabilities when incorporated into products that contain high levels of surfactant, solvents, and/or water, which results in the premature benefit agent release, (3) they can only effectively encapsulate a limited breadth of benefit agents, and (4) they either are so stable that they do not release the benefit agent in use or have insufficient mechanical stability to withstand the processes required to incorporate them in and/or make a consumer product and (5) they do not adequately deposit on the situs that is being treated with consumer product that contains capsules.
Accordingly, there is a need for encapsulated benefit agents, compositions, that eliminate or minimize one or more of the aforementioned drawbacks.